1. Field of the Invention
This invention relates generally to electrical lighting control devices and more particularly to a capacitive sense toggle touch dimmer.
2. Description of the Prior Art
A typical dimmer circuit adjusts the power delivered to at least one light bulb in response to a user touching a touch pad actuator. The touch pad actuator is “usually” made from metallic material. A small leakage current flows from the dimmer circuit to the user when the user touches the actuator. This flow causes the capacitance of the touch pad to change and a small voltage drop to develop across the user. A dimmer circuit can measure this change in touch pad capacitance and respond by adjusting, for example, the brightness level as well as the On/Off state of the light bulb. The dimmer circuit includes phase and neutral terminals which have to be connected to respective phase and neutral lines of an alternating current (AC) power source for proper operation. There are various well known techniques for measuring changes in capacitance. However, such techniques may not work properly if the electrical connection between the dimmer circuit and the AC power is reversed. That is, if the polarity of the connection is reversed, (phase line connected to neutral terminal and neutral line connected to phase terminal) then the dimmer circuit may not be able to sense or measure the small leakage current and capacitance changes in the touch pad and thus not operate properly.
It would be desirable to have a dimmer circuit that can operate properly even if the electrical connection between the dimmer circuit and the power source is reversed.